Move display preference code from ash/display/ to ui/display/manager/.

ash/BUILD.gn

Index: ash/BUILD.gn
diff --git a/ash/BUILD.gn b/ash/BUILD.gn
index 9e94b7c708d1eddd7f11045431a56ce4f0ca7cbc..c9882f088f0f7dbd4d3b782175ef03a33c1802cb 100644
--- a/ash/BUILD.gn
+++ b/ash/BUILD.gn
@@ -602,15 +602,12 @@ component("ash") {
     "display/display_configuration_controller.h",
     "display/display_error_observer_chromeos.cc",
     "display/display_error_observer_chromeos.h",
-    "display/display_pref_util.h",
     "display/display_util.cc",
     "display/display_util.h",
     "display/event_transformation_handler.cc",
     "display/event_transformation_handler.h",
     "display/extended_mouse_warp_controller.cc",
     "display/extended_mouse_warp_controller.h",
-    "display/json_converter.cc",
-    "display/json_converter.h",
     "display/mirror_window_controller.cc",
     "display/mirror_window_controller.h",
     "display/mouse_cursor_event_filter.cc",
@@ -1329,7 +1326,6 @@ test("ash_unittests") {
     "display/display_manager_unittest.cc",
     "display/display_util_unittest.cc",
     "display/extended_mouse_warp_controller_unittest.cc",
-    "display/json_converter_unittest.cc",
     "display/mirror_window_controller_unittest.cc",
     "display/mouse_cursor_event_filter_unittest.cc",
     "display/projecting_observer_chromeos_unittest.cc",